Centrifugal machine



Oct. 11, 1932. v w, MaclsAAC 1,882,390

CENTR IFUGAL MACHINE Filed March 2l, 1930 3 Sheets-Sheet l Oct. 11,1932. v W, MaclsAAC 1,882,390

CENTRIFUGAL MACHINE Filed March 21. 1930 5 Sheets-Sheet 2 Oct. 1l, 1932.v. w. MaclsAAc CENTRIFUGAL MACHINE Filed-March 2l, 1930 3 Sheets-Sheet 3Patented Oct. 11, 193 2 VERNON WESLEY MACISAAG, l' MONTREAL, QUEBEC,CANADA CENTBIFUGAL MACHINE Application med march 21, 1930. serial no.437,755.

The invention relates to centrifugal machines as described in thepresent specification and illustrated in the accompanying drawings thatform part of the same.

f, The invention consists essentially of the novel means employed ofutilizing the kinetic energy of the liquid passing through the machine.

The objects of the invention are to reduce the power customarilynecessary to be applied to the machine for the purpose of maintainingthe speed of the bowl and for the continual acceleration of theinflowing liquid .to the high velocities necessary for effectivedevelopment of centrifugal forces therein by usefully reclaiming anddirecting much of the kinetic energy of the liquid moving at highvelocity from the working section or sedimentation section of themachine and of the liquid entering the machine, heretofore ordinarilywasted; and thereby to supplement the usual means of applying power tocause rotation of the bowl and its contents in whole or in part byenergy derived from the inflowing liquid to be treated or separated andoutilowing liquid after treatment, the energy being supplied to theinflowing liquid either by gravity, by pump or other means of causingpressures and velocity; to cause the separator to act dynamically as ahydraulic turbine within which is provided a section or sections wherebyhigh circumferential velocities are obtainable with slight turbulenceand controllable radial thickness for the purpose of centrifugallysubsiding desired particles from the mass; to so arrange the structureof the rotating parts that the above objects may be attained withoutdiminishing the effectiveness of the machine as centrifugal separator orclassifier; and generally to provide a novel and eilicient means ofoperating centrifugal machines whereby power may be saved and the meansof applying it simplified and cheapened.

In the drawings, Figure 1 is a vertical sectional view showing arotatable bowl broken away intermediately and constructed for operationin a continuously flowing stream.

Figure 2 is a plan view of the feed end of the machine, showing thestationary inlet member broken away to disclose the spouting passages.

Figure 3 is a plan view at the dischargeend of the machine, disclosingthe outlet passages to the recovery impeller.

Figure 4 is a vertical sectional view of a modification of the machineshowing a contracted discharge opening with the recovery impellersfeature as a supplementary fea-V ture, in maintaining the momentum ofthe machine.

Figure 5 is a vertical sectional view showing a simple form of turbinecontaining a separator chamber.

Figure 6 is another modification of the machine showing the applicationof the recovery impellers to a machine containing a perforated separatordrum.

Figure 7 is a diagrammatic view showing the application of a pump indriving a plurality of bowls.

Figure 8 is aplan view of the interior of the cover .showing a turbinefeature of the bowl shown in Figure 4. Figure 9 is a plan view partiallyin section of the outside of the cover showing a turbine feature with aform of the invention shown in Figure 4.

Figure 10 is a plan view of the inlet and partially in section showingthe inlet end of the machine illustrated in Figure 4.

Figure 11 is a plan view of the inlet turbine and spouting member ofFigure 6J Like numerals of reference indlcate corresponding parts in thevarious figures. S5

Referring to the drawings, the bowl, indicated by the numeral- 15 is initself a rotor forming the turbine having the impellers 16 at the feedend and the recovery impellers 17 at the discharge end andVintermediatcly forming the centrifugal chamber of the separator, inwhich the heavier material is deposited on the inner wall surface bymeans of the centrifugal force developed in the rotation of the bowl.

This bowl at its lower end communicates with the intake 18 forming ascroll chamber 19 constituting the path to the turbine driving impellers16 through the spouting passages 20 in said scroll chamber, thedivisions 21 forming guiding surfaces as the infiowing fluid impinges onthe impellers 16.

The impinging of the liquid on the yturbine impellers 16 tends to setthe bowl 15 in motion, and the result is the separation of the heavierparticles which are deposited on the wall of the bowl in the customarymanner in centrifugal machines.

The bowl 15 is shown as flaring outwardly to form a collecting recess 22and may or may not have relief pockets from said recess aS. explainedmore particularly hereinafter, the inturned flange or rim 23 completingthe recess 22 and supporting the impellers 17 which are covered in bythe ring 24.

The liquid discharges continuously through the passages 25 and issuitably directed to a storage or other receptacle thus by adding thisrecovery turbine feature recovering energy customarily lost in theordinary dis- 'j charge of the liquid from a centrifugal maiso chine.

The wall of the bowl 15 may be cylindrical or tapered and is inturned atthe inlet end 26. The intake member 18 is rigidly supported by a fixedframe 27 extending from the outer'wall 28 of the scroll chamber 19, theinner wall 29 extending toward the impellers 16.

The turbinefeature carrying the impellers 16 is formed of the flangedring 30 having upstanding annular flange 31 and the outstanding annularflange 32 forming a recess 33 into which inturned end 26 of the bowlextends, the bowl being 'bolted to the flange 32, thus rigidly securingthel turbine ring and impellers to the bowl.

The bowl 15 is mounted on they main shaft 34 which is journalled insuitable bearings and keyed to the collars or'hubs 34 and 35 from whichthe radial arms 36 extend to the upper flange 23 of the bowl and arefixed thereto and the arms 37 extend to the turbine ring 30 and arefixed thereto, respectively.

The bowl may be installed to sit vertically, lie horizontally or slopein an intermediate position according to the circumstances of use and itis to be noted that the separating chamber or bowl under all conditionsconstitutes the momentum member of a driven turbine. In Figures 4, 8 and9 and 10, the shape of the bowl is changed with consequent changes andadditions to meet the different shape.

The bowl 40 is of frusto-conical shape having the inturned outer wall 41forming a central discharge opening 42 of lesser diameter than theoutside measurement of the inner shell 53.

The side wall 44 tapers from the wall 4'1 to the inner wall 43consequently the thickness of the liquid ringvmust depend on thedistance from the edge of the discharge openl ing 42 to the innersurface of the side wall 44 and this would not be practical in accom-.plishing the objects of this invention owing The shell 53 extends froma tubular'mount- A ing 54 keyed to the shaft 45 and slidable thereon andheld to the adjusted position by the set screw 55 and having the orifice56 or orifices to permit a reinforcing wall of liquid to form behind orinside the shell duri-ng the 'operation of the machine.

The shell 53 is of frusto-conical shape corresponding approximately tothe bowl in form, but of smaller dimensions, consequent- 'ly forming anannular passage 57 from the inlet end to the discharge end, whichassures the reduction in depth of the liquid treated and serves todirect the liquid or lighter material in its path 57 towards the outletthat must be along the inner surfaceof the outer end wall 41.

The impellers 58 project from the inner wall surface of the wall 41 andextend in radial directions to slightly beyond the edge of the dischargeopening 42 and are covered in by the ring 59 thus forming an innerrecovery turbine feature directly in the path of the discharge.

The thickened wall 60 insures a flat surface in a plane at right anglesto the axis of the machine and the impellers'61 project outwardly andacross said flat surface in a semispiral direction, thereby forming theoutlet passages 62 for the liquid and impact surfaces against which theliquid impinges on its way out and contributing the outer recoveryturbine feature for the acceleration of the rotation of the machine atan expenditure of energy of the leaving liquid that otherwise would bewasted. j

The intake 62 encircles the hub 47 and is in the form of a scroll casing63 having the spouting passages 64 between the curved divisions 65, butthis partitioning 'of the scroll chamber is not essential.

The flanged ring 50 extends outwardly to enclose the inwardly extendingflange 66 from the scroll casing 63, consequently the passage through tothe inlet 51 is guarded and in this intermediate passage the impellers67 are introduced and these impellers 67 project from the hub 47 and maybe the primary driving turbine feature of the machine.

It must be understood that in connection with the primary drivingturbine feature and the recovery driving turbine features that one orthe other of the features may be omitted, in fact many changes may bemade in regard from the spirit of the invention, which amongst otherthings is to benefit by the skin friction of the llquid on the bowleither in entering or in utilizing the energy accumulating from the highcircumferential velocities of the liquid in the machine.

In Figure. 6 the construction shows an adaptation of this invention tothe perforated drum t pe of centrifugal machine and in this form tlyieinner shell or liuid conductor 68 is supported by the radia arms 69 and70 from the hubs 7l and 72 respectively, and this shell is reduced atthe outer end 73 to form a primary driving turbine feature preferablyhaving the impellers 74 in the path of the liquid delivered through thespouting member 75, in a nearly tangential direction as shown in Figure11.

The perforated drum 76 extends at one end from the shell 68 and at theother end from the hub 72 and this drum 76 is surrounded by the casing77 forming an annular dischar e chamber 78 closed at oneend 79 and leaing to the annular discharge passage 80 projecting beyond both theperforated drum 76 and casing 77 in a direction at right angles to theaxis of the drum and in this passage the impellers 81 are introducedthus orming a recovery turbine feature similar to Figures 3 and 9through which the liquid must pass and in passing impinge on theimpellers 81.

In Figure 5 a very simple form of bowl is shown and indicated by thenumeral 82 having the inlet opening 83, through which the spoutingmember 84 is inserted and directed almost tangentially to the inner wallsurface of the bowl 82, similarly to member in Figure 11, the wall ofsaid bowl being inwardly flanged at the discharge end 85 to support theimpellers 86 covered by the vring 87. The bowl 82 is supported by theradial arms from the hub 88 keyed to the shaft 89, thus the spoutingmember 84 may deliver liquid at considerable speed to the bowl to impartrotation thereto and this liquid is treated and finds exit through thepassages 90 similar to passages 62 in Figure 9 and recovering energy toaid rotation.

The illustration in Figure 7 is for the purpose of showing theapplication of the invention to a multiple of machines these machinesbeing indicated by the rotating bowls 91, 92 and 93 mounted on shaftsjournalled in the bearings 94 and having turbine features 95, 96 and 97driven by running stream delivered from the pump 98 in the pipes 99,A100 and 101 branching from the delivery pipe 102 of the pump.

Briefly it may be said that the operation of this invention is mainlyconcerned in the utilization of the energy gained from the liquid underpressure or high velocity whether from the original stream or from thevelocity of the liquid by centrifugal action to an outwardly curved pathas enter but reduction of circumferential velocity does, that is to say,in the first place when the liquid is pumped into the machine or whenthe liquid flows into the machine under an kind of pressure, the primarydriving member of the centrifugal machine may be a turbine of any type,in other words, the whole machine becomes a water or liquid wheel drivenby th'e flow and in passing through the turbine feature into theinterior of the bowl, the liquid drives the machine and is then actedupon by centrifugal force and the heavier port-ion separated from thelight portion or the solids from the liquid as the case may be.

YAgain the liquid portion, which is progressing at a very considerablespeed, to the discharge due to the momentum of the large body, must seekan outlet, and this outlet is at the discharge end of the machine,therefore, the added force of the throw of the rapidlyA moving liquid istaken advantage of'and it is passed through impellers at the dischargeend Where it impinges on the impact faces in passage and .eventually isdelivered to the outside, thus much energy that might be otherwisewasted is recovered or as much of it as possible under the circumstancesand the efhciency of the machine itself is in no wise altered, in factif anything still greater eiiciency is secured by the employment of thisrecovery system.

rIhe impellers in the path of the discharging liquid are beyond thedischarge opening and outside of the bowl, forming backwardly andoutwardly curved passages through which liquid issuing from dischargeopening passes as it is thrown centrifugally outward.

The backward direction of passage causes useful recovery of energy fromthe leaving liquid tending to aid rotation of the bowl by reactivepressure of the outflowing streams against the forward faces ofpassages.

This may further be explained by considering a particle of liquidleaving the discharge rim 60, from point O. Its direction of travel ifunrestrained would approximate a line OA tangential to the circle ofdischarge and assuming unrestrained flight over a disc, the particlewould trace a path relative to said disc of an involut-e curve fromdischarge circle as the curve OV while its absolute direction of flightis OA. However, by interposing in its path, deflecting surfaces as shownhaving a sharply backward direction, the absolute motion of saidparticle may be defiected from its initial line of flight OA OB beingchanged in direction and reduced in velocity by the reaction of saiddefiecting surfaces and thereby pressing them to forward rotation as ina turbine. Indeed this may be considered a final stage of a turbine.

Again returning to inlet the liquid to be centrifugally treated entersunder pressure through the inlet and passing aroundthrough the scrollcasing 63, which is fixed to the stationary frame of the machine, it isdirected inwardly through spouting passages formed between divisionstoward the impcller vanes mounted on hub against which vanes the liquidimpinges imparting to them a reactive pressure tending torotate hub andshaft and all rotating members thereon mounted. As shown the spoutingmember comprising scroll casing and divisions between rings provides aplurality of spouting passages, but thls is not always necessary incertain cases.

The liquid entering between impeller vanes is deflected upwardly in thedirection ofarrows indicating fiow and is finally centrifugall f thrownoutward toward the shell and is discharged centrifugally outward overthe edge of the inlet ring towards the wall of the bowl whence it passesalong between bowl and inner shell towards the discharge being subjectedin this annular section between bowl and shell to an increasing degreeof centrifugal force which precipitates out heavier particles from themixture and deposits them on the inner Wall of the bowl.

This section of the bowl may therefore be termed a sedimentationsection. It is to be noted that in a liquid revolving with the bowl ofthe centrifugal machine the centrifugal forces are commonly from 300 to500 times that of natural gravity, so that the liquid tends to pressoutwardly in a ring inside the bowl having an inner diameterapproximating the diameter of central discharge opening. And in existingmachines intended for the purification of pulp, the minimum thickness ofthe layer of liquid being treated is determined by the diameter ofdischarge opening.

Now for the purpose of this invention it is desirable to reduce thediameter of discharge to much less than the inner diameter of the layerof pulp being centrifugally treated at high velocities inthesedimentation section because since the kinetic energy of the liquidleaving the bowl varies as the square of its velocity therefore if it bemade to leave at velocities approximating the rim speed of a smalldischarge opening asv compared with the high velocities near the outerbowl shell remarkable savings in power may be achieved by the recoveryof energy as the liquid moves from the section of high velocity to thedischarge rim of low velocity. To achieve this result and still be ableto constrain the pulp being treated to the comparatively thin layernecessary in centrifugal apparatus, the inner shell is provided withmeans for adjusting and as before mentioned, the adjustability in thethickness of said layer is attained by` making both bowl and inner shellconeshaped with the inner shell movable endthe crushing pressure fromwithout and v thereby permitting it to be light in construction.

As the liquid travelling at high circumferential linear velocity at thelarge diameter of bowl moves inwardly towards the discharge opening ofless circumferential linear velocity it tends to be slowed up to someeX- tent by friction on the cover wall surface but the inventionprovides additional and more effective means of reducing this velocityby the provision of impeller vanes between which the outflow towards thedischarge may take place restraining the liquid to a velocityapproximating that of the discharge rim and reactively causing rotationof the bowl in its passage toward the discharge. This assembly of innervanes in some instances need not be covered in with a ring.

What I claim is 1. In a centrifugal machine, frusto-conical bowlsuitably mounted for rotation and having a feed inlet at one end anddischarge at the other end, a frusto-conical inner shell commonlymounted with said outer bowl having an inner deflecting end in the wayof the feed inlet, and means for driving said outer bowl.

2. In a centrifugal machine, a frusto-conical bowl suitably mounted on ashaft for rotation therewith and having a central feed inlet at one endand discharge opening at the other end, a frusto-conical shell formingan inner adjustable member slidable on said shaft mounted in respect tosaid outer casing, and having a bottom end in the way of said feed inletopening, means for supporting said inner casing and distancing it fromthe bottom of said bowl and means for driving said shaft.

3. In a centrifugal machine, a frusto-conical bowl, an inner cone-shapedshell spaced 'from the wall of the outer bowl and from the bottomthereof and having a tubular iounting, a shaft for said bowl suitablymounted and carrying said shell and slidably keyed thereto, and alocking means holding,

said tubular mounting and fixedly determining the longitudinal positionof said shell.

4. In centrifugal machines, a bowl having inlet and an outlet, and aninner rotary shell forming an annular passage between itself and theinner wall surface 0f the bowl and having a liquid passage into theshell, said shell carrying a defiector adapted to accelerate the How ofthe liquid in its flow to said annular passage.

5. In centrifugal machines, a bowl mounted on a shaft and having aninlet and an outlet, an intake discharging into said inlet and having ascroll chamber encircling said shaft and causing a swirl in the iniowingliquid adapted to impart motion to the bowl and means for recoveringkinetic energy from the bowl discharge.

6. In centrifugal machines, a cylindrical bowl suitably mounted anddriven having aA feed end and a central discharge opening in theopposite end, an inner shell of greater diameter than said dischargeopening and mounted to rotate with said bowl and forming an annularfiuid passage between said bowl and said shell and having a head fordeliecting the incoming liquid-into the annular passage and means ofrecovering kinetic energy from the liquid adjacent to said dischargeopening.

7 In centrifugal machines, a bowl suitably mounted on a rotatable shafthaving means to impart rotary motion to said bowl and its contents fromthe power of incoming liquid and having an intermediate sedimentationsection, an inner deflecting shell completing said sedimentation sectionand adapted to divert the fiow of incoming liquid into any annular ringbetween said shell and said bowl and to constitute a passage to acentral discharge outlet between the shell and the bowl of less diameterthan said shell and means of recovering kinetic energy from the liquidleaving said sedimentation section previous to passing said dischargeoutlet and after passing said discharge and to discharge said liquidfrom the rotating members at a velocity much less than its linearvelocity within the said sedimentation sections.

8. In centrifugal machines, a bowl and a shell spaced to form anintermediate fluid wall directed to the outlet and turbine means 45having impellers with surfaces receding from the direction of rotationand adapted to form discharge channels in the path of the tan'- gentialfiow of the liquid for driving the bowl.

9. In centrifugal machines, a bowl having an inturned flange at thedischarge end forming a head encircling the outlet opening, means fordriving said bowl. and a shell spaced to form a restricted and shallowpas- 55 sage to the head of the bowl, turbine blades arranged in saidoutlet for supplementing the driving power.

10. In centrifugal machines, a bowl having an inturned liange at thedischarge end form- 60 ing a head and a surface deflecting the dischargeof liquid inwardly and a shell cooperating with thist deliecting surfaceand forming an annular shallow passage from the inlet to the head of thebowl, a turbine mountc5 ed on the inner wall surface of the head in thepath of the outgoing fluid, and means for driving the bowl.

11. In centrifugal machines, a bowl suitably mounted for rotation andhaving an inturned flange at the discharge end, means for drivingopenings between the blade members supplementing the main driving means.'12. In centrifugal machines, a bowl tapering from an inturned dischargeend to an inturned inlet end, a turbine element introduced 1n the pathof the liquid liowing into said bowl, a turbine element introduced inthe path of the liquid on the inner face of the-inturned discharge endanda turbine element introduced in the path of the liquid on the outerface of said inturned discharge end.

13. In centrifugal machines, a plurality of bowls suitably mounted forrotation and having inturned ends surrounding inlet openings, turbineelements introduced at said inlet ends, stationary inlet chambersencircling said turbine elements land inlet pipe lines leading to saidinlet chambers, a feed pipe common to said pipe lines, and a pumpconnected to a source of supply and forcing iuid into said common feedpipe. i

14. In centrifugal machines, a bowl suitably mounted and driven andhaving an inturned head to a central discharge opening, means forrecovering kinetic energy in the line of the discharge and means forconstricting the fluid to a shallow body in passage from the startingend to the inturned head aforesaid.

15. In a centrifugal machine, a bowl suit-- ameterthan said dischargeand constricting the Huid to a shallow annular layer within the bowl inpassage from the starting end to the inturned head end aforesaid andinwardly projecting vanes mounted within the bowl on the inturned headand with said head constituting channels directing the How of fluid fromthe aforesaid shallow annular layer towards the discharge opening.

16. In a centrifugal machine, a bowl having an inwardly hanged rimportion forming an overflow member for the comparatively clear liquid,driving turbine blades at said rim, an inlet channel member closing theother end of said bowl and directing the inflow, and driving bladesattached to said bowl at the inlet end and introduced in the path of theinflowing liquid.

17. In centrifugal machines, aperforated bowl open at one end suitablymounted for rotation and having a suitable inlet and an outer casingfixed in relation to said bowl and forming a discharge chamber having anannular outwardly extending discharge passage between turbine bladesbackwardly curved in respect to the direction of rotation to receive akinetic push from the force of 5 {zhe loutfowing Huid to aid rotation ofthe Si ned at Montreal, Canada, this 13th day of lfarch 1930.

VERNON WESLEY MAOISAAC.

